546  COLORING  MATTERS  OF  FLOWERS. 
their  vat,  which  gives  considerable  brightness  to  the  tint.  It  is 
easy  to  prove  also  that  acids,  even  when  very  weak,  cause  the  dis- 
appearance of  the  greater  part  of  the  color  of  a  decoction  of  woad. 
From  this  it  seems  not  improbable  that  the  substance  which  com- 
municates to  white  flowers  the  property  of  becoming  yellow  when 
in  contact  with  alkalies  may  be  luteoline. 
If  the  petals  of  white  roses  be  boiled  with  distilled  wTater,  and 
a  little  carbonate  of  soda  and  sulphate  of  copper  be  added  to  the 
decoction,  as  is  done  with  the  decoction  of  woad,  a  liquid  is  ob- 
tained possessing  a  bright  golden-yellow  color,  which  may  be  era- 
ployed  in  dyeing  yellow.  This  liquid  will  give  a  fine  yellow  tint 
to  linen  and  cotton  fabrics,  and  nearly  all  white  flowers  will  fur- 
nish similar  results.  I  have  dyed  pieces  of  linen  and  cotton  with 
decoctions  of  white  roses,  of  the  flowers  of  Spircea  filipendula, 
Philadelphus  coronaria  and  Galium  mollugo. 
The  matter  to  which  white  flowers  are  indebted  for  this  property 
of  acquiring  a  yellow  color  under  the  influence  of  alkalies,  dis- 
solves readily  in  water,  still  more  so  in  alcohol,  but  less  in  ether. 
When  the  superficial  layer  of  the  petals  of  flowers  which  have 
been  colored  yellow  by  ammonia  is  removed,  all  the  cells  are  seen 
to  be  filled  with  a  yellow  fluid,  in  which  no  granules  are  to  be 
perceived. 
Dark  Red  Flowers. — With  boiling  water  or  alcohol,  the  flowers 
of  the  wild  poppy  furnish  a  violet-red  solution.  This  acquires  a 
fine  scarlet  color  by  the  action  of  acids,  even  when  very  weak. 
If  ammonia  be  poured  into  the  liquid  thus  acidulated,  it  becomes 
of  a  fine  violet  color,  without  the  least  mixture  of  green.  But 
if,  instead  of  adding  ammonia  to  the  acidulated  liquid,  it  is  added 
directly  to  the  infusion,  this  acquires  a  dirty  greenish-red  tint. 
When  the  flowers  themselves  are  exposed  totheaction  of  ammonia, 
they  acquire  a  fine  violet  color,  like  thai  obtained  with  the  acidu- 
lated fluid.  The  coloring  matter  of  the  poppy,  therefore,  differs 
greatly  from  the  cyanine  of  MM.  Fremy  and  Cloez,  for  alkalies  do 
not  give  it  a  green  color. 
The  flowers  of  Pelargonium  zonale  also  become  of  a  fine  violet 
color  under  the  influence  of  ammonia;  their  coloring  matter  be- 
haves like  that  of  the  poppy.  The  dark  red  garden  verbena  gives 
a  violet-red  tint  to  alcohol.  The  alcoholic  solution,  treated  with 
ammonia,  acquires  a  vinous  color  with  a  slight  greenish  tint.  If 
